Document processing devices include printers, copiers, scanners and e-mail gateways. More recently, devices employing two or more of these functions are found in office environments. These devices are referred to as multifunction peripherals (MFPs) or multifunction devices (MFDs). As used herein, MFP means any of the forgoing.
Toner-based print engines of MFPs utilize a transfer belt unit (TBU) as part of the printing function. Toner is selectively attracted onto one or more photoconductive drums of an electrostatic process unit (EPU) in accordance with an image to be printed. The TBU transfers the toner from the photoconductive drums onto the paper, after which the transferred toner is then fused by heat onto the paper and delivered to a tray for retrieval by a user. Like any other parts of a printer, TBUs can become worn from use and have limited life cycles, and therefore need to be periodically serviced or replaced.
Removing the TBU for maintenance or replacement is time consuming and can require a skilled technician to perform the function. Before removing the TBU, a technician typically must first disengage the drive shaft from the TBU. For example, the technician may be required to remove one or more panels or other parts from the printer in order to first access the drive shaft before the technician can manually urge the drive shaft away from the TBU. Once the technician places a TBU back into the MFP, the technician must reverse the steps and reengage the drive shaft with the TBU. If any steps are not performed or are performed incorrectly, for example if the drive shaft is not disengaged or engaged properly, the TBU or other parts of the printer can be damaged during subsequent print attempts. For these reasons, replacement of the TBU is generally not performed by the end user customer, but instead is performed by an experienced technician during a service call. However, service calls are an added expense and can take time to schedule. A malfunctioning TBU can result in down time for the MFP until the TBU is serviced or replaced.